Measured-service telephone system.



T. G. MARTIN.

MEASURED SERVICE TELEPHONE SYSTEM.

APPLICATION FILED JAN.17, 1907. 1,169,102. Patented Jan.18,1916.

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APPLICATION mu) JAN 11 1907 Patented J an. 18, 1916.

3 SHEETS-SHEET 2.

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E APPLICATION FILED JAN. '7. I907 1,169,102, Patented Jam-18, 1916.

3 SHEETSSHEET a.

TALBOT G. MARTIN,

OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

FIRST TRUST AND SAVINGS BANK, TRUSTEE, OF CHICAGO, ILLINOIS.

MEASURED-SERVICE TELEPHONE SYSTEM.

Specification of Letters Patent.

Application filed January 17, 1907. Serial No. 3'52,693.

, matic or semi-automatic telephone exchange systems, and especially to commonbattery systems.

Broadly considered, my invention contemplates a measured service telephone system in whichthere are call-registering devices allotted to the difi'erent subscribers stations and controlled by the called subscribers. With such arrangement, a calling subscriber obtains connection in any suitable manner with the line of the called subscriber, but the call is not registered until the called subscriber answersthat is to say, it is the act of the called subscriber in answering which actuates the meter or call-registering device of the calling subscriber for the purpose of registering a successful call.

More specifically considered, my invention contemplates a call-registering-- device""or' meter which is located at the exchange or central station, or at the terminal of the subscribers line, and which is always controlled or actuated by the called subscribers.

My invention also contemplates a system in which automatic means are provided andcontrolled by the calling subscribers for trunking through the exchange and into connection with the lines of the called subscribers, and in which call-registering devices or meters are allotted tothe different subscribers lines and associated with the first-selectors or other suitable individual switches at which the different subscribers lines terminate.

7 Furthermore, my invention contemplates a system in which call registering devices are allotted to the difl'erent subscribers lines and provided with coils or relay windings through which battery current is fed to the calling subscribers lines for talking purposes.

My invention also contemplates certain other features of novelty and combinations and details of construction, as will hereinafter more fully appear.

In the accompanying drawings, Figures 1 and 2 taken together are a diagram of an Patented Jan. 18, 1916.

established connection between a ca ling and a called substation. The calling substation is shown at Aand the called substation at A. For the purpose of explaining my invention, the substations may be considered as being at the same or different exchanges; but in this case the substation A, the line #500 to which is allotted the switch C,

shown in Fig. 1, and thesubstation A, the

line #220 to which is allotted the switch C, together with the connector switch D, are considered as belonging to the same exchange. For operating the central office switching apparatus a central current source B, is provided having its positive terminal preferably grounded. Between the said substations there is shown the connecting central oflice switching apparatus comprising switches characterized by many well-known features. The selector switches C and C are a modification of the selector switch disclosed in United States Letters Patent No. 815,321, granted March 13, 1906, to Keith,

Erickson and Erickson. Fig. 3 is a diagram 7 of the first-selector and the meter The s bstations A ar rd A like substations usually employed in connection with switches of the aforesaid type, are each provided with a dial which the subscribers op-.

erate for sending impulses over the'line to operate the switches at the central oiiice. They are provided, in addition, with the usual telephone switch-hooks through the medium of which the substation ground circuit, the release circuit, and the primary,

secondary and ringing circuits are suitably submitted to the control of the subscribers.

The substation A may be of any suitable or approved type. The one in connection with which I ave elected to illustrate my invention comprises a. receiver 2, and a switch-hook 3 for controlling the substation circuits, which controlling operations are accomplished through the medium of any suitable means, such as the cam arms 4, 5 and 6;

. As the switch-hook is lowered, the cam arm 4 momentarily presses the release springs 7 I 8 and 9 into engagement, whereby the substation line conductors -may be grounded simultaneously. When the switch-hook is down, the cam arm 5 maintains a contact be: tween the springs 10 and 11, thereby bridging the ringer 12 in series with the condenser winding '6; but when said springs are together,

ground is then provided to the ground post 16 and ,to thegrelease spring 7 as is usually the case intelephones'of this type, The said substation comprises the usual transmitter 17 and induction-coil18, the latter having the primary winding 19 and secondary 20. Said substation is also provided with the usual vertical and rotary im-' pulse springs 21. and 22,and is,of course, provided with a dial (not shown) secured to the shaft, and withthe lockingdog 23. Furthermore, there is a locking. cam 24 that locks the dog 23, while the receiver is on "the switch-hook, to prevent, a rotation of the dial. For operatingthe impulse springs 21 and 22 the substation isprovided with an impulse wheel 25 that is secured to the shaft 1 26, "which impulsewheel carries on its pe-.

rlphery the vso-called vertical impulse teeth 27? and one rotary impulse tooth 28- The said impulse teeth are so arranged that when the dial is drawn down the impulse springs 21 and 22' are not carried into contact'with the ground post 16;-but as the dial returns, first the vertical teeth engage the vertical impulse spring 21,v and after they have completed their work the rotary impulse tooth operates the rotary impulse spring 22. In

this operation the subscribers vertical line conductor 27 is first given a number of ground impulses, and then the rotary line conductor 28 is given one ground impulse.

It will be noticed that as long; as the'dial is,

out of normal position the construction is such that the dog 23 permits the primary circuitsprings 29 and 36 to'separate, thus preventing the impulses that are delivered to either line conductor from passing to this other; Means whereby a subscriber may signal a called subscriber comprises the push-button 31 which, when pressed, carries the spring 32 out o'f engagement with the contact 'point 33 and into engagement with thecontact point 34, wherebythe vertical line conductor 27 is grounded.

type of selector switch disclosed in United States Letters Patent No. 815,321, above re- The selector switch C is of the general ferred to, except that the so-called side switch is omitted and the circuits modified accordingly. Among other details the selector switch '0, in connection with which my meter mechanism is shown, comprises the usual vertical and rotary line relays 35 and 36'which in turn control the vertical and rotary magnets 37 and 38, respectively.

By means of the fingerarm 39, the rotary magnet in turn operates the armature 40 of the private magnet 41, which latter maintains its own energizing circuit under condi- ,tionsjsrwilllbelexplalnedr The release of release magnet 42, which latter is controlled by the vertical and rotary liner-clays 35 and)" it After the switch has operf line leadingto a second swltch,the' release I 36 conjointly. ated and established connection with a trunk magnet 42 is controlled from the second switch through the release relay 43. Fur-a, thermore, when theconnection is established I with the next succeeding switch, the line i I ,a

switching relay 44 operates to disengage the line conductors 27 and 28 from the vertical and rotary line relays 35 and 36, and vto'extend the said line conduiztors to the seized L trunk line through the wipers 45 and 46 which, withthe private wiper 47, are carried.

upon the switch-shaft48. Under the con i trol of the shaft cam49 are the cam springs is 1 I 50, 51 and 52 which, when the shaft is in a,

rotated position, maintain a guarding po-' tential at the connector bank over the private normal conductor 53, through the springs '51 and 52, for protecting the lineaL; t 'lotted' to the switch. Furthermore, the

switch-draft {i8 is provided with a normal arm 54 which, when the shaft is in an operated position, permits the springs 55'and56 to engage,whereby an energizing circuit is closed through the off-normal lamp 57 when This occurs when the switch-shaft the cam springs 50 and51 are in engagement. is in a vertically operated position only; Now when the shaftreceiVes a rotary impulse,-the cam 49 passes from the control/of T I i passes out of engagement with the spring the said camsprings, wherebylthe spring 51 50 into engagement with the spring 52, I The relays comprised in my meter or registering arrangement are the relays 58 and 59' which are connected in series with the windings 60 and 61, respectively, of thedifferential relay 62. The said relays, 58 and '59 are so arranged a that 'whencboth relays energize simultaneously, the springs 63 and 64 then engage; but when either r'elayoperates alone the springs 63 and 64 do not. engage' The relay 62 operatively energizes when the two windings 60 and 61 are connected in series; but when the windingsare ti vely energize, since thesaid windings are dlfi'erentially' arranged; and when current a f in multiple the said relay, doesnot opera-" passes 'through the windings in multiple, as

stated, the windings 60 and 61 then oppose V vided for operating the meter register 66, g

each other. The meter magnet 65 is pmwhich can be of any suitable construction,

as the exact character of; the numerals, wheels or registering mechanism 'is unim-y portantL. The condensers 67 and'68divide the circuit through theswitch into two sections and, serve to increase the efliciencyof I Y the talking circuit.

The connector sw thh j mayalso be of any suitable or approvedtype, for instance 189 of the general type described in United States Letters Patent No. 815,176. The mechanical details of the selector and connector, as is well known, are very much the same, although there is a difference in the circuits. For instance, the connector switchshaft which is not shown carries, like that of the selector, the line wipers 69 and 70 and the private wiper 71. The connector switch is also controlled by the calling subscriber through the medium of the vertical and rotary line relays 72 and 73. The vertical line relay 72 directly controls the vertical magnet 74 and also the rotary magnet 75. The ofiice of the vertical magnet 74 is to give the shaft and shaft wipers a vertical motion, and the rotary magnet 7 5 imparts to the shaft and shaft wipers a rotary or circular motion. The rotary line relay 73 controls the private magnet 76 which, under certain conditions, in turn controls the vertical and rotary magnets 74 and 75, the re-,

lease magnet 77, and also the side switch wipers 78, 79, 80 and 81. The said side switch, like the side switch of the selector, has a normal or first position, a second position and a third position. The release magnet 77 is also controlled by the vertical and rotary line relays 72 and 73 conjointly. By the use of the condensers 82 and 83 the connector divides the circuit through it into two sections to separate the calling and called subscribers talking current feeding circuits, for well known reasons. The connector is provided with a differentially wound relay 84 which is composed of the windings85 and 86. The function of this relay is to enable the calling subscriber to release and to energize the ringer relay 88 for signaling. Said relay provides the means by which the ringer generator E is bridged across the terminals of the called line to signal the called subscriber. back-bridge relay 87, comprising the windings 89 and 90, provides the calling subscriber with talking battery current when the primary circuit of the called substation is bridged acrossthe line. The central station is equipped with the busy signaling apparatus F of any suitable design, as, for ex ample, the onecomprising an interrupter 91 in series with the primary winding 92 of the induction-coil 93, whereby a busy signaling current is induced in the secondary winding 94 of the said induction-coil. The secondary winding 94 is connected with the side switch wiper 79, through the normal springs 95 and 96, when the side switch is in first position and when the connector switch-shaft is raised.

The operation of my meter device may be more clearly understood by following its action when a subscriber calls another subsJ'riber and-the called subscriber answers. Suppose, for example, that the subscriber The at substation A calls and signals the subvertical line relay 35 of the selector C, which in turn operates to close an energizing circuit through the vertical magnet 37. The vertical line conductor 27 being grounded twice the vertical magnet 37 energizes twice to raise the selector shaft 48 and wipers 45, 46 and 47 two steps. The said wipers are carried opposite a level in which are the contact points that constitute the terminal of the trunk line leading to the connector switch D. Following the vertical impulse the rotary impulse operates the rotary l1ne relay 36 which, upon energization, closes a circuit; then the rotary magnet 38 rotates the shaft wipers 45, 46 and 47 onto the first set of contacts, and the rotary magnet arma ture 97, by means of the arm 39, operates the private magnet armature 40, whereby the springs 98 and 99 engage and close an energizing circuit through the said private magnet, if the first trunk line is busy. This private magnet circuit extends' from the grounded private wiper 47 through therelease relay 43, private magnet springs 98 and 99, private magnet 41, through the release magnet springs 100 and 101 to the battery lead 102, thence through battery B to ground G. The private magnet 41, upon energizing, maintains an energizing circuit through the rotary magnet 38 extending from ground Gr through the private magnet springs 103 and 104 to the rotary interrupter springs 105, thence through the rotary magnet 38 to the battery lead 102, thence through battery B to ground G. The rotary magnet, by continuing to rotate the wipers, breaks the energizing circuit of the private magnet 41 as soon as an idle trunk line is found. If, however, the first nine trunks are busy, the shaft wipers will be rotated onto the tenth set of contacts or tenth terminal, the trunk line allotted to which terminal, it will be assumed, being idle and upon which the wipers come to rest. When the private magnet 41 deenergizes a guarding potential is established at the enbattery lead 102 thence through battery B to ground G. It will be observed that the rotary: magnet 'is included in; this circuit; but since the relay of twenty-t'hree 1 s hundred ohms resistance, and. the rotary magnet of sixty ohms resistance, there: is not w suflicient current passing 'to 'operatively en-' 7 ergize the said 'rotary'magnet; f 1

The line switching relay, as previously explained, operates to disconnect the sub: scribers line conductors 27 and 28 from the vertical and rotary line? relays and 1 36,"

respectively, and to extend the said conductors to theshaft' wipers and 46an'd to the trunk conductors 107 and'1'08 which lead to the connector-ID. The grounding ofthe line conductors '27 and2-8 for the last two digits affects the connector by operating the e vertical and rotary line relays 72; a'nd 73. Whenthe said vertical line conductor 27 is grounded the vertical line relay 72 is ener gized by a flow of current fro-mthe substation ground G, Vertical impulse spring-21 to the vertical line conductor 27, line switching relay springs .109 and 110, relay 58, I winding of the'diiferential relay 62, shaft wiper 4:5, conductor 107,vthrough theconnector vertical line relay 72', winding 85, of

the difierential relay 84 to the b'attery lead 102, thence through battery'B to ground 1G. The relay 58 and thewindings 60 and 85 of the relays 62 and 84, respectively, being included in this circuit, the said relays energize, but their operation at this particular 1 timeis without effect. Each time that the e vertical line relay 72 operates forthe second I ential relaySi, through the springs 113 and.

digit, the ,yertical magnet o-peratively energizes to carry the shaft wipers 69, and 71 in a vertical direction one step at a-time until the said wipers are carried two steps and thus brought opposite a level'in which g are located the terminals of the line #220.

.Vhen the rotary line conductor 28 is grounded the connector rotary linerelay 73 becomes energized through a circuit extending from, the substation ground G through the rotary impulse spring 22, rotary line conductor 28, line switching relay springs "111 and 112, relay 59, winding 61 of the relay 62, shaft wiper 46, conductor. 108, rotary line relay 73, winding 86 of the differnew the battery lead 102, thence through battery B to ground G. The windings of the relays 59,62 and. 84 being included in effect. The rotary line-relay pletes'an energizing circuit throughthe pri vate magnet, which latter now operates with a this circuit as in the vertical'line relay cirv I cult, the sald relays energlzejbut WltlL no ,1

V 73, upon ener-x I glz ng, operates to close an energizing c1r-' cuitthro-u'gh-the private magnet 76,rwhichi70 I -latter in turn operates to release the side switch fr'omfirst to"second-position For the last digit-the subscriber operates the dial, as previously described," grounding the ve1-- tical line conductor27 ten times and the rotary line conductor 28 once The connector -.vertical and rotary line relays 72,and 73 are operated over previously traced circuits! However, when the vertical line relay operates, a circuit is closed throng-l the"rotary 30 I magnet 75 instead of through the vertical magnet 74. Each time that the rotary mag- I net energized the shaft wipers 69, 70 and 71 are rotatedone step at a time until the said wipers are carried into engagement with terminals of the desired: substation. The

rotary line relay 73, uponenergizing, com:

one of two results, viz, the release of the side switch from second to third position, or the so-called busy release of the connector. It will be assumed that the former result occurs and that the side switch passes to third position, whereby the side switch wipers 78; and 79 are placed in connection with the shaft wipers 69 and 70, respectively. Fura y e thermore, when the side'switch passesto third positiona guarding potential is esltablished for protecting the called line.

The said guarding potential also closesan, energizing circuit through the line switching relay 118 of the selector C, which relay operates to close the springs 119 and 120 W and 121 and 122 in contact, whereby the I normal conductors 115 and116 are extended to the line conductors 123 and 12twhich' I lead to substation A. The circuit through the line switching relay 118 extends from I ground G through the side switch wiper 80, to the connector shaft wiper 71 (Fig. 1), to

the conductor 117 (Fig. 2), thence through the winding of the line switching relay 118, interrupter springs of the rotary magnet, winding of the rotary magnet to the battery 7 lead 102, thence through battery B to ground G.

In order to signal, the subscriber at sub-, station A presses the Signaling button 31, whereby the vertical line conductor 27 is grounded, and the connector vertical line relay 72 and thedifl'erential relay 8 be come energized as before. It willbe re-izzmembered that the side switch has passed from second to third position and the ide I switch wiper 81 is in engagement with the contact point 130, thereby placing the ever e tical line relay 72 in control of the ringer 85 the normal conductors 115, 116 and 117,"the'- e first two of which conductors lead to the line relay 88 in the same manner in which the rotary magnet 75 came under the control of the vertical line relay when the side switch passed from first to second position. Therefore, when the vertical line relay'presses the springs 126 and 127 into contact the ringer relay 88 is energized by a fiowof current from ground G? through the springs 126 and 127, private magnet springs 128 and wiper 81, contact point 88, springs 131 and 132, that the differential relay to the, battery lead 102,

- the terminals of the ringer generator E. A

- 122, rotary winding signaling current is therefore sent from the generator E to the ringer relay springs 137 and 136, side switch wiper 78, contact point 138, shaft wiper 69, normal conductor 115, line switching relay springs 119 and 120, vertical line conductor 123, condenser 139, ringer 140, springs 141 and 142 to the rotary line conductor 124, line switching relay springs 122 and 121, rotary normal co'nductor 116, shaft Wiper 70, contact point 143, side switch wiper 79, ringer rela springs 133 and 135 back to the generator As soon as the calling subscriber ceases to press the Signaling button 31 the ringer relay 88 becomes deenergized and the springs 133 and-136 resume their normal position. The subscriber at substation #220, in response to the signal, removes the receiver 144 from the switch-hook 145, which allows the springs 146 and 147 to engage, and.

the springs 141 and 142 to disengage, thereby removing the ringer 140 from across his line. The engagement of the springs 146 and 147 closes aseries energizing circuit through both windings of the relay 87 at the connector D, this circuit extending from ground G to the contact point 148, side switch wiper 80, winding 90 of the relay 87, through the ringer springs 134 and 133, side switch wiper 79, contact point 143, shaft wiper 70, rotary normal conductor 116, line switching relay springs 121 and line conductor 124, primary 149, transmitter 150, through the signaling device of the called substation, through the springs 146 and 147, vertical line conductor 123, line switching springs 120 and 119, conductor 115, shaft wiper 69,

contact point 138, wiper 78, through the winding 89 of the relay 87, springs 151 and 132 to the battery lead 102, thence through battery B and to ground G. The relay 87, upon energization, operates to shift the spring 113 from the spring 114 (which lat- B and to ground ter is connected to the battery lead 102) to the spring 152, which latter Is in turn connected with ground. The reversalof the polarity of the spring 113 sets up a circnit which.provides the calling substation with battery current for talking purposes. This circuit may be traced from ound Gr to the contact point 148,, side switch wiper 80, through the springs 152 and 113, winding 86 of the differential relay 84 rotary line ft wiper 46,

relay 73, conductor 108, sha winding 61 of the differential relay 62, relay 59, line switching relay springs 112 and 111, rotary line conductor 28, primary winding 19, transmitter 17, springs 29 and 30, vertical line conductor 27, line switching relay springs 109 and 110, relay 58', winding 60 of the differential relay 62, shaft wiper 45. conductor 107, vertical line relay 72, winding 85 of the diiferentialrelay 84 to the battery lead. 102, thence throu h battery B and to ground G. Since tlie windings of the relay 58, 59 and 62 of the meter mechanism are included in this circuit,rthe said relays energize simultaneouslv, the relays 58 and 59 closing the springs 63 and 64 1n contact, and the relay 62 closing the springs 153 and 154 in contact, whereby an energizing circuit is established through the meter magnet 65 from ground G, through the springs 63 and 64, springs 153 and 154, magnet 65, and to the battery lead 102, thence through battery B to ground G.

The meter magnet, upon energizing, attracts its armature 157, whereby the pawl 158 engages the teeth of the meter wheel 159, rotating said wheel one step, which is registered on the meter 66. Furthermore, when the armature 157 operates, the springs 155 and 156 engage, thereby closing a second or locking circuit through the meter magnet 65. This locking circuit. extends from ground G through the cam springs 51 and 52, meter ma net springs 155 and 156, through'the said meter magnet to the battery lead 102, thence throughbattery B and to ground G. The function of this second circuit is to maintain the meter magnet in an ino erative condition until the calling subscri er restores his receiver to the switch-hook, which results in the release of the switches employed, and the restoration of the cam springs 50, 51 and52 to normal position-that is,-the spring 51 disengages from the spring 52 and closes in contact with the spring 50, thus destroying the loclc ing circuit of the meter magnet. If this locking circuit were not provided, then if for any reason the called subscriber should restore his receiver to the switch-hook and again remove the same before the calling subscriber releases, battery current for talking purposes is cut oil from both the calling and called substations and again supplied, which would again energize the .relays 58,

' 69 and-62 simultaneously; thus again energizing the meter magnet 65wh1ch would operate a second; time, To prevent the meter fromfthus registering twice. for one Qcall the locking circuit is provided' The release ofthe switching apparatus is brought about when thejicalling subscriber thereby pressing the release springs 7, ;8 and restores the receiver 2-to the sw1tch-hook3,

Qintoengagement for a moment. :The con- ;tact of the said'release springs groundsthe vertical and rotary line conductors 27 and .28 simultaneously from ground-Gr to the release spring 7 thence through the springs 8 and 9 to'thevertical and rotary line conductors. Thegro unding of the rotary line conductor-28, roduces a short-circuit of the rotar relay j '3 series with the winding 86 0 theid-iiferential relay 84, said circuit extendingv from ground G at the connector to the contact point 148,'side .switch w1per '80,springs 152 and 113, winding 86 of the I tore, since the Winding- 85 of the difiz'erendifi'erential relay 84, rotary line relay 73 to the shaft wiper'i46, winding 61, relay 59, line switching relaysprings 112 and 111 to the rotary line; conductor 28, release springs 8 and 7 to thesubstation ground G. Theretial relay 84 ,alone carries current, the said relay becomesenergized and attracts its armature, which shiftsthe spring 132 out of "contact withhthe spring 151 into contact with the spring131. The disengagement of the springs 151 and 132 destroys the energizing circuit throughthe. relay 87, and the spring 113 passes out of engagement with the spring, 152and into engagement with the spring 114, which removes the said short-circuit of, the rotary relay 73 and winding 86, and establishes an energizing circuit instead extending from the substation groundG through therelease springs 7 and 8 to the rotary, line conductor 28, then 'torthe,.rotary1ine relay 73, as previously traced, winding 86 of theidifl'erential relay 85, through the springs 113 and 114 to bat tery lead 102, thence through battery B'te ground G. The rotary relay 7 3 now oper ates and the springs 160 and 161 come into contact, whereby an energizing circuit is established through the release magnet 77 of the connector D and the release relay 43" 'p f/the selector C; However, the current now in passing, as above stated, through the winding 86 aids the winding inmaintaining the springs 131 and 132 incontact. The

energizing circuit through the release relay 43 and release "magnet 77extends from ground G at the selector C, private magnet energ zes, and as a result the" switch-shaft and side switch are restored to normal position, thus breaking theconnection between '7 71 and the normal conductors 115,116 and theconnector switch-shaft wipers 69, 70 and f i The back-release relay 43 being inthe'same circuit with the release magnet energizes simultaneously with the latter and operates to close a circuit through the selector release magnet 42 by pressingtogether the back-H release springsl64 and 165. The circuit" through'the said release, magnet 42 extends from ground through therelease springs 164 and165 to the releasema e642, thence to the battery lead 102, and t rough battery B to groundfG. When the ground to the line conductors27 and 28is interruptedall the magnets involved in'therelease, are ,de-'

energized and all the switches are fully restored. I When the switch C is fully restored the cam spring 51 passesout of engagement with the spring 52, whereby the'locking cir-' cuit through the meter magnet '65 becomes broken and the said magnet returns to nor? atthe time that the calling subscriber#500 attempts to establish connection, theconnector D is released by the last impulse to the l rotary line conductor 28, as follows: The

said impulse energizes the rotary linerelay 73 oftheconnector D, which relay in turn it energizes the private magnet .76, pressing the private springs 166 and 167 into contact after the private wiper 71' has been carried [loo onto the grounded privatebank contact. 1 Of course, it is understood that whenever a line is busy the connector private bank contacts all connected to ground. Therefore, since connected with the private normal 117 are I the connector side switch is in second position when the private springs 166 and 167 are brought into contact, anenergi zingcircuit is established through therelease'magcontact to the privatewiper71, thence to the side switch wiper 80J(which]is in second a net 77 from the said grounded private bank position) to the private magnet springs 167 and 166, to the release magnet-77, through the springs,131 and 132 to the battery lead 102,thence to the batteryB and to ground G. The connector switch-shaft and side switch I are thus released and connection is not established with the called line. calling subscriber presses the signaling button, the vertical line relay 72 becomes energized and operates to close a circuit through Now, when the I the vertical magnet 74. The vertical magnet operates to carr the switch-shaft vertically, whereby the o -normal springs 95 and 96 engage to permit the busy signaling current topass to the calling subscriber in the usual way. Of course, when the subscriber hangs up his receiver afterrreceiving the busy signal,he grounds the linerelays 72 and 73 of 90 mal position. If the called line #220 is busy) 1 tors 27 and 28 are grounded and current passes through the meter line relays 58 and '59 and through the windings 60 and 61 of "the differential relay 62, the said relays 5S and 59 energize, but the relay 62 does not energize and, therefore, the springs 153 and 154 do not engage, and, of course, since the meter magnet 65 does not become energized the meter does not register. a

The relays used in my meter device may be wound to any suitable resistance, but good results have been obtained when the relays 58 and 59 are wound to a resistance of thirty ohms each, the windin s of the relay 62 to a resistance of thirty 0 ms each, and the meter magnet to a resistance of one hundred ohms.

From the foregoing it will be seen that I provide call-registering devices which are operated by the called subscribers to register the successful calls. As illustrated, these call-registering devices or meters are located at the exchange or central station, but it is obvious that for the broader purposes of my invention they may be located at other points in the general system. Furthermore, t will be seen that these call-registeringdevice's or meters are, after registering a call, always looked against further actuation, so that a disconnection and restoration are always necessary before a meter can be caused to register. another call. registering devices or meters are provided with coils or relay windings through which battery current is fed to the lines of the calling subscribers for talking purposes.

It will be understood, of course, that all of the difierent contacts or circuit-controlling devices can be adjusted or regulated in any suitable or known manner for the purpose of obtaining the desired results and the described mode of operation. It will also be understood, of course, that the first-selector C has a bank of trunk line terminals for use when the subscribers line to which it is allotted is used as a calling line. Should the subscriber at substation A. call the subscriber at substation A, the call-registering device or meter allotted to the first-selector C will then be controlled or actuated by the subscriber at substation A, in order to register the successful call. Should the subscriber at substation A not answer, however, no registration of the call will be made, as previously explained;

What I claim as my invention is:

1. In a telephone exchange system, the

combination of calling and called telephone lines, an automatic switch controlled over the calling line, means for registering the call as soon as the called subscriber answers, and means including said called telephone In addition, these call-' line and a difierentially wound relay individual to the calling line, but normally disconnected therefrom, for controlling the registering o erations of said means.

2. In a te ephone exchange system, the combination 0 connectors for makin the final connections with called telephone ines, automatic means for trunking calling common battery telephone lines into connection with said connectors, call-registering devices allotted to the different telephone lines for registering the calls as soon as the called subscribers answer, and means including a diflerentially wound relay individual to the callin line, but normally disconnected there rom, by which'the called subscribers cause said devices to register the calls.

3. In a tele hone exchange system, the combination 0 ,telephone lines, automatic means for connecting calling lines with called lines, including common battery connectors for finding the called lines, callregistering devices allotted to the different te ephone lines, responsive to the called subscribers for the registration of calls, and 90 means including the called telephone lines and a dilferentially Wound relay individual to the calling line but normally disconnected therefrom, for controlling the said devices and causing the same to register all successful calls.

4. In a telephone exchange system, the combination of a calling telephone line, a called tele hone line, a common battery or centralize source of talking current, a "call- 1 registering device allotted to the calling line, a hook-switch for the called line, means responsive to the action of said hook-switch for admitting talking current to the calling line, means including a differentially wound 105 relay responsive to said hookswitch for causing the said registering device to register the call, and means for locking said device against further operation while the two lines are connected.

5. In a telephone exchange system, the combination of calling and called telephone lines, a plurality of trunks, an individual automatic trunk-selecting switch for the calling telephone line, a relay temporarily 115 energized to maintain the continuity of the talking connection between the two lines,

a call-registering device allotted to the said individual switch and adapted for register ing the call when the called subscriber answers, and means including line relays by which the called subscriber causes said device to register the call.

6. In atelephone exchange system, the combination of a calling telephone line. a call-registering device provided with a dii ferentially-wound electromagnet, and a battery connected to'supply current through the said difierential windings to the calling line for talking purposes.

" 7. In a, tele hone exchange system, the.

combination; a calling telephoneline a call registering'device providedwith a differentially-wound electromagnet, a battery connected; to sup 1y current through the said difierential windings to the calling line for talking urposes, and a called telephone 7 line over w ich the called subscriber conwith a relay temporarily ener 'zed to mainlines, a call-registerin tain thecontinuity of theta king connec tion between the two lines, atoll device allotted to ,the calling tele hone line, and

means bywhich thecalle subscriber con-' trols said device to cessful call.

9. In a telephone exchange system,f the combination of a calling telephone line it called telephone line, means including'a p u} assessjtoll for the sucrality :of automatic switches for extend-' 25 two lines, and a call-registering device al-,

lotted to the calling telephone line, provided with a relay also] temporarily energized du ingtalking.

10. In. a te ephone exchange system, the. combination of a calling telephone line a called telephone line, means including a'p u-' rality of automatic switchesfor extending a connection from a callin scribers line,,a relay in ividual to a subscriber and temporarily energizedto maintain talking connection .between the two the calling telephone line, provided with'a relay also temporarily energized during-1' talkmg, and means by which the called sub-r scriber controls the 1, said device to register;

' of. talking current, and a call-registering dethe call. V 11. In a telephone exchange system, the

combination of a calling telephone line acalled telephone line, means including a p urality of automatic switches for extending a connection from a calling to a called subscribers line, a relay individual to the calling telephone line and temporarily ener-;'

gized to'maintain talking connection between the two lines, a toll device allotted to the calling line, and means for operating said toll device when the called subscriber answers.

12. In a telephone exchange system,- the combination of a calling telephone line, a called telephone line, means including a plurality of automatic switches for extending a connection from a calling to a called subscribers line, a relay temporarily energized" to maintain the continuity of the talking -between"t e two telephone lines, provided combination go 1n "a connection-froma calling to a called, su scribers line, a relay individual to a; subscriber. and temporarily energizedfto-f maintain talking connection betweenfjtheto a called sub-.

device allottedfto the called'subscriber controls the supply of connection the two lines a call- I registering device allotted to the calling line,- means b which the called subscriber operates i sai device to register" the call,. and means for locking'the; said deviceiag'amst further operation while the; two lines are connected.

13. In a telephone exchange systenr, the 1g: combinationjof a calling telephone 11116, a

called telephone line, a relay temporarily energized togjznaintain the continuityiof the talking connection between the twolines, automatic meansforatrunking; the calhn'g}: line into: connectionwith the calledlme,

controlled byithe calling subscriber a'trunkrelease circu t, which circuit 1 includes no portion of the talking circuit a call-regi's tering device allotted tofthe c ling line, and.

means for, disconnecting the two .lines and restoring said callsregistering device by the closure of said trunk-release circuit;

'- 14. Ina tele' honekiexchange system, the f a" temporari y established talking circuit, a c'all registering device pro- 'vided with adilferentiall'y-w'onnd relay, and

means for supplying talklng current through the windings of said relay'to the said talking circuit, the said call-registering device provided with a local operatingcircuit controlled by said relay.

r 1 5. Inaftelephone system,- means includinga d-ifi'erentially wound relay having one windingiconnected to each side of the talking circuit, by which the called subscriber controls the supply of talking current to the substation of the callingsubscriber, and a call-registering device comprising a-rotary element and meansfor actuating the same responsive to the flow, of talking. current to the cal-lingsubscriber.

'16. In a telephone system, means by which talking current-to thecalling' subscriber, a

fdifierentially wound relayv individual to the callingsubscriber and responsive to'the flow vice "controlled by said relay.

'17; In a telephone exchange system, the

\ combination of a calling telephone line, a call-registering device provided with a differentially-wound electrom'agnet, a battery connected to supply current through the said differential windings to the calling line for talking purposes, and means having one motion to'select groups and another motion to connect with the called line in any group selected by the first motion of the same means, both mptions controlled overssaid line from the substation thereof,

18. In a telephone exchange system, the

combination of a calling telephone line, a

I combination of a calling telephone line, a

called telephone line, a relay temporarily energized to maintain talking connection between the two lines, a call-re istering device allotted to the calling telep one line, provided with a relay also temporarily energized during talking, and means having one motion to select groups and another motion to connect with the called line in any group selected by the first motion of the same means, both motions controlled over said line from the substation thereof. 1

20. In a telephone exchange system, th

combination of a calling telephone line, a called telephone line, a relay individual to the calling telephone line and temporarily energized to maintain talking connection between the two lines, a toll device allotted to the calling line, means for operating said toll device when the called subscriber answers, and means having one motion to select groups and another motion to connect with the called line in any group selected by the first motion of the same means, both motions-controlled over said line from the substation thereof.

21. In a telephone exchange system, the combination of a calling telephone line, a

called telephone line, a call-registering 'clevice allotted to the calling line, means by which the called subscriber operatessaid device to register the call, means for locking the said device against further operation while the two lines are connected, and means having one motion to select groups and another motion to connect with the called line in any group selected by the first motion of the same means, both motions controlled over said line from the substation thereof.

22. In a telephone exchange system, the combination of a temporarily established talking circuit, a call-registering device provided with a difi'erentially-wound relay, means for supplying talking current through the windings of said relay to the said talking circuit, the said call-registering device provided with a local operating circuit controlled by said relay, and means having one motion to select groups and another motion to connect with the called line in any group selected by the first motion of the same means, both motions controlled over said line from the substation thereof.

23. In a telephone system, a differentially wound relay individual to the calling subscribers line, responsive to the called subscriber, a call-registering device controlled by said relay, and means having one motion to select groups and another motion to connect with the called line in any group selected by the first motion of the same means, both motions controlled over said line from the substation thereof.

24. In a telephone system, a differentially wound relay individual to the calling subscriber, a call-registering device controlled by said relay, means by which the called subscriber energizes said relay when he answers, and means having one motion to select groups and another motion to connect with the called line in any group selected by the first motion of the same means, both motions controlled over said line from the substation thereof.

' 25. In a telephone system, means by which the called subscriber controls the supply of talking current to the calling subscriber, a

differentially wound'relay individual to the lotted to each calling line for registering such connections, a pair of line relays and a differential relay individual to the calling line, and means for energizing each of said line relays in series with a winding of said differential relay to control said meter.

27. In a telephone system, means for extending a connection between a calling and a called subscribers line, a service meter allotted to each calling line for registering such connections, a pair of line relays and a differential relay individual to the calling line, and means for energizing each of said line relays in series with a winding of said differential relay and in series with the talking circuit to control said meter.

I 28. In a telephone system, means for eX- tending a connection between a calling and 30. In 'a telephone system, subscribers lines, common battery means for supplying change system; a side switchless trunk se-' of said double-wound relay in series in each side of the talking, circuit and a call-registering device controlled by said relays. n 31. In a measured service telephone exlector having vertical'and rotary motion allotted to the calling'line, and acall registering device associated with said selector con trollable over the called line.

Signed by me at Chicago, Cook county, Illinois, this 11th day of January, 1907.

TALBOT. G. MARTIN.

Witnesses:

EDWARD .D. FALES, ARTHUR B. SPERRY.

I is 

